The present invention relates generally to a universal joint and, more particularly, to an assembly wherein a trunnion cross interconnects the yoke arms of two yokes of the assembly. More specifically, the invention relates to an assembly wherein upon the trunnion of the cross there are arranged hollow cylindrical bearings or bushings which may contain roller bodies, with the bushings being received in bores of the yoke arms and being axially fixed. The invention is particularly directed to the configuration of seal means interposed between the bushings and the trunnion cross.
Universal joints are known in the prior art, for example, from German Pat. No. 2,618,536, wherein for insuring maintenance-free lubrication during the service life of the assembly, there is provided a supply of lubricant between a continuous elastic seal which covers the body of the trunnion cross. However, such a construction is no longer used in larger trunnion crosses since it is uneconomical to manufacture. In trunnion crosses which are used, for example, in the construction of rolling mills, the cost for providing a coating of, for example, plastic material is so high due to the large diameters involved that they are no longer acceptable from a practical, economical viewpoint.
In view of the foregoing, the present invention is directed to the further development of a trunnion cross having a large diameter which nevertheless provides economical and inexpensive utilization of material, and which permits maintenance-free lubrication of the joint during its service life by insuring a supply of lubricant.